NEW YORK, April 27 (Reuters) - A lawsuit against fitness equipment maker Nautilus, Inc was revived on Monday, when a U.S. appeals court ruled that a heart rate monitoring patent the company is accused of infringing is valid.
The long-running case had made its way up to the U.S. Supreme Court, which last year changed the way lower courts determine whether a patent is so vague it should be thrown out.
On Monday, the U.S. Court of Appeals for the Federal Circuit, the nation's top patent court, said the patent owned by Biosig Instruments, Inc was not too vague, remanding the case back to the lower court to proceed with the lawsuit.
Biosig, based in Quebec, Canada, first sued Nautilus in 2004, alleging infringement of its patent for monitors built into exercise machines that measure electrical waves to estimate a user's heart rate.
The lower court had said the patent was invalid because it was "indefinite," or too vague to be eligible for legal protection. On appeal, the Federal Circuit in 2013 overturned that ruling because it said the patent was not "insolubly ambiguous."
Vancouver, Washington-headquartered Nautilus asked for a review by the Supreme Court, which made it easier for courts to find patents indefinite in its decision in the case last year.
The high court then sent the case back to the Federal Circuit, which maintained that the Biosig patent was not ambiguous, remanding the case back to the lower court.
John Vandenberg, an attorney for Nautilus, said the company was disappointed but emphasized no decision had been made on infringement. Biosig attorney Mark Harris said the company was pleased.
The case is Biosig Instruments, Inc v. Nautilus, Inc, in the U.S. Court of Appeals for the Federal Circuit, No. 12-1289.
Reporting by Andrew Chung; editing by Alexia Garamfalvi and Richard Chang